replace internal object description string with a configuration

[dixx]

This is related to the 3D object creation #22.
Most of the time, a C++ configuration object is way faster and a bit smaller than a string.
Check why we use the string in the first case, and check if it would be a good idea to replace it with a proper configuration object.

[dixx]

We use a string as it is a flexible data type with simplest handling. And of course it is a good idea to replace a struct with a proper object, which is extendable at wish. But think about a good object structure first!
... and a string is version-safe.

[dixx]

example:

class ObjectConfiguration
{
    string name;
    enum type;
    io::path meshFileName;
    core::vector3df position;
    ;
    ;
    ;
}

[dixx]

We should think about replacing even the scriptual string creation, as well as the stack handling.
We could read the values "as is" from the stack, but we would need a marshaling (a more or less unchangeable order) or an "encoding" for this, and a bit of logic must may also be in the Lua scripts. We could even think about creating the whole objects in Lua. Maybe this relates to #8.

[dixx]

Or we just use a class holding a JSON or YAML object instead, with defaults and accessors.